AASHTO T253:02(2020) Standard Method of Test for Coated Dowel Bars.
1 .1. These methods are designed to test the qualifications of the organic coating of corrosion-resistant dowel bars to withstand the effects of weathering, deicing chemicals, and the abrading and loading stresses experienced in field joints.
1 .2. The units of measure to be used shall be either SI units or inch-pound units (shown in parentheses in this standard) depending on the units used in the applicable material specification.
1 .3. The values stated in SI units are to be regarded as the standard.
2. REFERENCED DOCUMENTS
2.1. A A SI-ITO Standards:
• R 39, Making and Curing Concrete Test Specimens in the Laboratory
• T I 06M/T 106, Compressive Strength of Hydraulic Cement Mortar (Using 50-mm or 2-in.
Cube Specimens)
2.2. ASTM Standards:
• Dl 4741D1474M, Standard Test Methods for Indentation Hardness of Organic Coatings
• G8, Standard Test Methods for Cathodic Disbonding of Pipeline Coatings
• G12, Standard Test Method for Nondestructive Measurement of Film Thickness of Pipeline
Coatings on Steel (withdrawn 2013; replaced by D7091)
• G14, Standard Test Method for Impact Resistance of Pipeline Coatings (Falling Weight Test)
• G20, Standard Test Method for Chemical Resistance of Pipeline Coatings
3. MATERIALS AND APPARATUS
3.1. The concrete design and constituents shall comply with the procedure and specification stated by the purchasing or specifying agency.
3.2. Suitable containers, molds, and miscellaneous concrete mixing equipment necessary for mixing and casting the simulated doweled joints for load, pullout, and corrosion tests to meet condition stated in R 39.
3.3. An abradometer capable of operating at 60 to 70 double strokes per minute using 100-mm- (4-in.) long strokes.
3.4. Universal test machine capable of operating accurately in the 0- to 45-kN (l0,00() lbf ranges and capable of controlled stress and strain rate loading.
3.5. Suitable hold-down devices for positioning and holding the casting in place without rotation during the flexure tests.
3.6. Freeze—thaw equipment of sufficient capacity to handle the pullout and corrosion—abrasion test specimens.
3.7. Sufficient quantities of chemical to maintain solution for corrosion tests.
4. PREPARATION OF SAMPLES
4.1. The coated dowels for deflection tests may he in support baskets or loose. The coated dowels for the remainder of tests shall he loose.
4.2. Type A—coated dowels shall he cast without additional coating of any kind. Type B—coated dowels shall be covered before casting with the dehonding agent specified by the coating manufacturer.
4.3. The prepared dowels shall be cast in the appropriate molds specified for the various tests.AASHTO T253 pdf download.